The role of this type of valve is to allow only the medium to flow in one direction, and to prevent the direction of flow. Usually the valve is automatically working, in a direction of the flow of fluid pressure, the valve flap open; fluid flow in the opposite direction, by the fluid pressure and the valve flap from the valve seat in the valve seat, thus cutting the flow.

Which check valve belongs to this type of valve, which includes swivel check valve and Shanghai Lianggong valve factory lift check valve www.lgvf.net. There is a hinge mechanism, and a door like a valve flap free to lean on the surface of the inclined seat. In order to ensure that the valve flap reaches the proper position of the valve seat each time, the valve flap is designed in the hinge mechanism so that the flap has sufficient swivel space and the flap is truly and fully accessible to the valve seat. The flap can be made entirely of metal, or it can be embedded in metal, leather, rubber, or synthetic coverage, depending on the performance requirements. Swing check valve in the fully open condition, the fluid pressure is almost unimpeded, so the pressure drop through the valve is relatively small. The flap of the lift check valve is located on the valve seat sealing surface of the valve body. This valve in addition to the valve can be free to lift, the rest as the same as the valve, the fluid pressure so that the valve from the valve seat sealing surface lift, the media back to the valve back to the valve seat, and cut off the flow. Depending on the conditions of use, the flap may be of the all-metal structure or in the form of a rubber pad or rubber ring in the flap frame. Like the shut-off valve, the passage of the fluid through the lift check valve is also narrow, so the pressure drop through the lift check valve is larger than the swivel check valve and the flow of the swivel check valve is limited Very few

Check valve common faults and treatment methods Common faults are:

① valve broken;

② medium back flow.

The cause of the disc flap is:

Check valve before and after the media pressure is close to the balance and each other "see the saw" state, often with the valve seat beat, some brittle materials (such as cast iron, brass, etc.) made of The disc is broken. The precautionary approach is to use a check valve that is a ductile material.

The reason for the media backflow is:

① seal surface damage;

② entrapment of impurities.

Repair sealing surface and cleaning impurities, you can prevent backflow.